I always find it a bit sad when I see people bashing religion in this otherwise civil, tolerant community. I think ganzfeld puts it well, and I'd like to expand on that: mocking what people do and say, even if motivated by religion, is all well and good. But to mock a person's personal beliefs is, at best, in very poor taste.

Yes, it has been used as a tool to maintain tyranny and oppression, there are also plenty of wonderful, rational people--some of them on this very board, in fact--who hold their faith as a comfort and an inpsiration; and to call these people liars or the victims of liars does them a disservice.

So you feel that a religious text is a work of fiction. Fine. But it's a lot more than that as well. In addition to its social relevance, it is a collection of philosophical and ethical treatises that was compiled over centuries, whose contents have been constantly discussed, debated, and reinterpreted even up to today. It's an important historical document - both in that it has influenced the course of history since the day it was written, and in that it contains a great deal of insight and information about many disparate ancient cultures. Even if you hold that literally nothing in the Bible actually occurred in any way, shape or form (which would be a very simplistic, even naive, thing to contend), it still shows us how people acted, how they thought, and how they believed they should act and think. It's not just the muttered ramblings of some crazy guy in a cave.

So looping back to the OP, of course it's relevant whether or not hell as we know it is included in the earlier tracts! Historically and anthropologically, it matters because it gives us insight into the worldviews of earlier peoples, and how they may have absorbed or adapted certain ideas from neighboring cultures. It shows us how their practices and beliefs mirror or differ from those of modern practitioners. In short, it gives us one more detail to consider in of the story of humanity.

And if you still choose to believe that the Bible is nothing but a work of fiction, with no importance or relevance beyond that, I'll just say this: so is Star Wars, but it still "matters" whether Han shot first.

Edit: Somewhat spanked by thorny and hambubba; both make very good points that mirror and complement what I was trying to get across.